Conductor for oil-well heaters



June 17, 1930. G. w. KNOX CONDUCTOR FOR` OIL WELL HEATERS Filed Feb. y21, 1,927 2 sheets-sheet 1 INI/ENTOR, nm/

v' ATTORNEY.

G. w. KNox 1,764,213

CONDUCTOR FOR OIL WELL HEATERS Filed Feb. 21. 1927 2 sheetssheet 2 June 17, 1930.

ATTORNEY.

illlll I l l i l l l IJ@ Il l l1 Patented June 17, 1930 oFFlcE GEORGE WASHINGTON KNOX, F OKLAHOMA CITY, OKLAHOMA coNnUc'ron non OIL-WELL -nEATEns Application led February 21, 1.927.. `S'Aelial-N'o. 169,983.

This invention rlates to methods of and means for heating the products in oil Wells for the purpose of increasing the flow or capacity of such wells and facilitating the delivery of the products above ground.

It is well known that after a iiush production in oil wells, there is usually a gradual decline of production until the operations of the wells become unprotable but it has been found in practice that supposedly depleted wells may be revived and restored to profitable production, through a method and means of heating the deposits inthe bottoms of @the wells, such bottomsY being usually termed the shot holes, and the surrounding oil producing sands of formations.

The sluggishfcharacter of the wells leadving to the apparent depletion is due to a number of causes, but the most prevalent heavy oil, or the presence of paraflin, whichy retards the flow of oil into the shot hole from the oil producing sands and lessens the productivity of the well.

It has been found in practice and it is well known that the application of heat to the contents of the shot hole and oil producing formations surrounding increases the fluidity of the said cntenits and brings it in condition where it. can be expeditiously pumped and this, of course, results in reducing the pressure against the infiow of oil in the well, from the surrounding oil pnoducing formations.

It is an object of this invention to provide means for heating the contents of the shot I hole and for displacing the deposits immediately in contact with the heater in order that deposits of lower temperature may be brought into contact withtheheater successively and displaced as heated so thatthe said heated deposits may be circulated and transmit heat to the oil sands and the heavy hydrocarbons be taken up by the pum or other applied me hods and delivered a ove ground.

It is a further object of this invention to produce a heater for an oil well in which' delivery of the current or the circuit for the,

current includes a well casing as one of its cause of such sluggishness is the presence of.

paths, or in which the said circuit includes the pump tubing-and the sucker rod asone e of its paths, or a circuit which includes the casing as one of the paths or leads' and the tubing and the sucker rod as another of saidv 55 leads.

. Itis furthermore an object of this invention to produce novel means whereby the circuits tov and from the heater are segregated against accidental short-ing, yet including contacts andconnections by which a `circuit through these vinstrumentalities may be maintained.

' It is still a further object of this inven- `toin to provide a tubing-having a plurality of insulators removably applied to it, and efective to prevent shorting of the circuit between the tube and the casing and to equip the pump operating means and the head ofthe casing with means for insuring proper operation of the heater.

With the foregoing and other objects in view, the invention consists in the Adetails of construction, and in the arrangement and combination of parts to be hereinafter more fully 'set forth and claimed.

In describing the invention in detail, ref-v erence will be hadI to the accompanying drawings forming part'of this application, wherein like characters denote corresponding parts in the several views, and in which- I e Figure 1 illustrates a sectional view of Aa well casing, showing a heater installed in thexshot hole associated with` the casing; I

Figure 2 illustrates a sectional view ofthe device on theline 2 2 of Fig. 1 f Figure 3 illustrates an enlarged detail sectional View of a casing and the tube, with an insulator applied thereto;

Figure 4 illustrates a sectional view of the tube, indicating the relation of the standingwand working valves of the pump'- ing ,barrel or apparatus to the tube;

Figure 5 illustrates a sectional view of the heater insulator; yFigure 6 illustrates an enlarged sectional View ofthe insulator and the tube and parts associated with them;

Figure 7 illustraties a detail sectional view of the coupling for the pump;

cates with the interior of the casing as a part of the usual equipment. The tube 18 may be of known construction and, of course, is made up of lengths of tubing having appropriate couplings 19, it being the usual practice to have such tube extend practically the full length of the well in order that the working and standing valves of the pumping barrel Will be submerged in the deposit of the shot hole.

The tube has insulation 17a where it passes through the head, and the tube is insulated from the casing, in the present embodiment of the invention, by a plurality of insulators which are preferably of uniform construction, and a description of one of them will sulice as a disclosure of their structure and means of anchorage, to one skilled in the art.

Preferably, each insulator consists of a cylindrical central portion 21 greater diameter than the tube, and a plurality yof radially disposed fins 22 project from the said central portion,l but they terminate in spaced relation to the internal bore of the casing. They are in such relation to the casing that lateral movement of the tube relative to the casing Will cause the insulators to engage the casing and prevent` the tube'from contact with the casing. The number of fins is preferably minimized in order that free circulation of gas `or water may be permitted ,in the casing, and the v fact that the fins do not extend to the wall of the casing also affords a clearance for the circulation of gas and water so that pressure may be relieved through the gas line. 18. Preferably the insulators when applied to the tubing are retained just above the joints between the sections of the tubing, although, of course, this is not an absolute necessity. In the present embodiment of the invention, however, the insulators are shown Aas encircling the tube atthe joint or coupling on a gasket 18, which will serve to prevent displacement of the insulator in a downward direction on the tube, as when the tube is being pulled from thev casing. Furthermore, the fins have rounded corners which serve to prevent lodging on shoulders or other obstructions at the joints ofthe of slightly casing. Each insulator is preferably held in place by a substantially constructed wedge 18b with corrugations or crimps 18c that are tapered from the upper end to the lower end of the wedge and the wedge is inserted between the insulator and the tube forced therein by mechanical pressure, to a degree which Will insure retention of the insulator by friction.

An insulator is provided at the lower end of the tube and, in the present embodiment of the invention, it comprises a c lindrieal core 23 having a plurality of ra ially disposed ribs 24 whose edges are notched to form seats 25 in whichv the resistance ele ment' or wire 26 is seated. The seats in the ribs are differently spaced in the several ribs in order that when the resistance element is wound on the insulator, it will be in spiral form. In order to produce this result, the location of the seats from the upper ends of the ribs is progressively increased around the insulator, as will be understood.

The number of ribs may vary and whereas four such ribs have been found sufficient as anchorages for the resistance element, more than that number may be employed, as illustrated in Fig. 5. Preferably, the ribs have holes such as 27 in them, through which ties may be introduced, for securing the resistance element and preventing its displacement in the event of the insulator becoming fractured or impaired.

' When installing the insulator on the tube, guard insulators 28 and 29 may be stationed above and below the end of the insulator.

The resistance element 26 is sho-wn as connected to the tube by a conductor 30,

whereas the other end of the resistance elewith the casing. The brush or wiper 32 comprises a plurality of blades preferably of resilient metal, whose central portions 33 are secured on a tubular insulator 34, which insulator encircles thetube 18, by which the brush or wiper is supported-.The electrical connection between the cable 31 and the casing may, of course be of different constructions, but the one here shown has been found satisfactory in use and it comprises a series of blades of resilient metal, as stated whose ends are bowed or bent outwardly from the centralanch'ored portions so that the said blades bear against the inner wall of the casing.

`As a means for supplying current to the heater, a suitable source of electricity, such as a generator 35, may be employed, having a conductor 36 leading to the casing and a conductor 37 leading 4to the tube.

The polish rod 38 attached to the upper end of the sucker or pumping rods operates through a head or stuffing box 39 at the top of the tube, and the oil outlet pipe 40 has an insulated joint 41 with the nipple or outlet pipe 42 leading from the tube. rod is connected to the walking beam or rod operating mechanism 43 through means of trunnions 44, which trunnions project from a housing 45. Apertured insulators 46 and 47 extend downwardly and upwardly, respectively, from the housing 45 and the rod 38 extends through said insulations. The rod is further insulated from the trunnions by a cylindrical insulator'48 fitting in the housing and surrounding a collar 49 between the insulators 46 and 47, to which the rod 38 is secured by a fastening 50, such as a setscrew or the like. on the housing bears against the upper-insulator 47 and by this means the parts areheld,

assembled. The insulation for the trunnions just described is to insulate the rods -from the forms one part "of casing and ground, which v the circuit through the walking beam or the casing. The insulationfor this part of the structure will,

beam and the nowise damage, fracture, or destroy it.

In order to insure high conductivity between the heater and the source of electricityl and the ground, the sucker rods and workmg valve are provided wit-ha' contact 52, here shown as an electrical contactor which moves .in contact with the inner WallI lof the tube 18, and this contactor constitutes a.

S5 member of a circuit through the working.

be built or placed around the head of the casing and the connections for the conductors.v

of electricity `and other parts of the mechanism. This shield may be in the nature of an expanded metal colunm, or it. may be of any appropriate and efficientl type without regard to material, its shape or other details.

Whil'e the inventor Shas supplied herein a description which to some extent is directed to the details of construction and relation of parts, it will be understood that changes in the proportions and the types of insulators and joints may be changed to suit particu- 69 lar requirements and duties, and the inventor does not wish to be limited with respect to these features, except as they may be included in the claims of the patent.

While the specification has been directed more particularly to the description of the The polish i A removably applied plate 51` v ofcourse, be of such strength l 25 and ruggedness that the lifting action of the V thrust action thereof will in -a well. casing,

p the heater and tube,

. rodengaging the tube, an

circuits in association wir.,A the heater of the open type, the same mechanism and circuit orming means have been used with equal success in heaters of the closedl type which are employed in wells havingsalt water and other mixtures which preclude the use of heaters of the open type.

The insulators 28 and 29 have vertically disposed holes 28a near their edges,

through which the conductors may be threadf ed from the heater. Any other desirable form of connectionA to any type heater may be employed, either at will, or as the occasion dema ds. y

In Fig. l1 the insulatorv54 is 'shown as applied to thecoupling -55 and the coupling may be provided with an annular channel 56 forming a seat for the insulator, and there may be a. corrugated joint 57 between the coupling and the insulator' which will inf crease the resistance\to displacement of the insulator with respectto'the coupling. I claim:

.1.*An ou well heater comprising an electric heater, a vwell casing, pump tube therein,

means for insulating the pump tube from the well casing, means for electrically connecting -the heater and casing including brushes mounted on and insulated from the tube engaging the said casing, andl a conductor from said brushes to `the heater, meansv for electrically connecting the .heater and tube, and conductors from asource of electricity to the casing and tube.

2. `In an oil well heater, an electric heater, a pump'tube therein, means for insulating neans for electrically connecting the heater preferably i the tube from the. casing,

and casing, means for electrically connecting a sucker rod in the tube, an electrical contact carried by the sucker electrical connection between the tube and the sucker rod at approximately the top of-safid tube, and conductors from a source of electricity tothe casing and tube.

3. A pump tube, a sucker rod therein, means for electrically connecting the lsaid tubean'd rod, yan electric heater at the lower end of the tube, a source of electricity, and

an electric circuit including said source of electricity and heater, one e ement of which circuit comprises the tube and rod.

4. In a heater'for oilwells, a casing, a' nl tube therein, an electric heater in the oil well, means for establishing a circuit to the heater through the said casing and tube,

means for insulating the tube from the cas- 'ing consisting of a plurality of `insulating elements applied to the tube, and a wedge interposed between the tube and the insulator for frictionally retaining the insulator in place; l

5. In a heater for oil wells, a casing, a tube therein,

an electric heater in the oil Well, means for establishing a circuit to the heater through the said casing and tube,

means for insulating the tube from the casing consisting of a plurality of insulating elements applied to the tube, and means for l holding each insulator on the tube at dierent positions of adjustment, said means comrismg a substantially cylindrical Wedge aving downwardly tapered ribs adapted to be forced between the tube and insulator.

6. ln a heater for oil Wells, acasing, a

tube therein, a sucker rod, an electric heater and a circuit for current for the heater, one element` of which consists of the casing and the other the tube and sucker rod, and means for insulating the sucker rod romsits associated elements.

GEORGE WASHNGTON KNOX. 

